Gas operated firearm with a movable gas cylinder functioning as an inertia member



March 13, 1962 R. H. WILD 3,024,706

GAS OPERATED EIREARM WITH A MovABLE GAS CYLINDER EUNCTIONING As A INERTIA MEMBER Filed Aug. 24, 1959 I7 INVENTOR.

ROLF H. WILD Hmm Patented Mar. 13, 1962 3,024,706 GAS OPERATED FlREARll/l Will-l A MVABLE GAS CYLINDER EUNCTEC'NENG AS AN 1N- lERTlA MEMBER Rolf H. Wild, Hamden, Conn., assigner to Olin Mathieson Chemical Corporation, a corporation of Virginia ldiied Aug. 24, 1959, Ser. No. 835,763 4 tClairns. (Cl. SSL-193) The present invention relates to gas operated firearms and in particular deals with a gas control device associated with such firearms.

Iniirearms of the gas operated typeinwhich propellant gases are tapped from the barrel `and employed to drive a piston which actuates the gun action, it is often desirable to have some means of regulating the energy transmitted to the piston. This is especially desirable in firearms which are adapted to lire a variety of types of ammunition, each developing widely varying pressure characteristics in the barrel.

Obviously, if no control device is provided to compensate for the varying pressures, the gun must be designed to function with that round of ammunition which develops the least gas pressure energy on the operating piston. However, when firing rounds which develop high pressure levels, excessive energy is transmitted to the action which tends to increase wear and tear and shortens the `life of the firearm. To avoid this occurrence it is desirable to control the gas energy transmitted to the operating piston in such manner that, essentially, a constant amount of energy is transmitted independent of the type of round being tired.

In a `co-peno'ing application, S.N. 796,087, tiled February 27, 1959, by Rolf H. Wild etal., now Patent No. 2,987,967, there is disclosed a control device which is sensitive to pressure and time and which bleeds excessive gases to the atmosphere as soon as a certain value of energy or a sustained impulse has been transmitted to the piston.

The present invention provides a ditferent means for accomplishing a similar purpose by providing a valve embracing an inertia sensitive metering element which controls the admission or" gases from the barrel to the working piston. 'lhis inertia responsive element is conditioned by the recoil of the gun prior to the occurrence of gas ow from the barrel to the piston. Depending7 upon the power of the gun recoil the valve is operative to preset the proper restriction or throttling effect in the gas conduit leading from the barrel to the cylinder before gas begins to llow,

The recoil movement of a shoulder firearm is dependent jointly upon the power of the round being tired, upon the weight of the firearm and upon the resistance provided by the shooter. For practical purposes the resistance provided by the shooter does not signilicantly affect the initial gun recoil movement, at least up to the instant of gas ow from barrel to the cylinder. The time interval of the initial recoil measured from the instant of firing up to the point of gas admission into the cylinder is of the order of 1 to 2 milliseconds and results in a comparatively small displacement of the overall gun. Consequently, the variation in resistance provided by various shooters is a negligible factor at this early time.

The initial increment of recoil movement can be ernployed to sense differences in ammunition power and to condition a gas control device which includes a freely movable element. Thus, diderent values of initial recoil operate upon the movable element to establish a corresponding number of different relative positions, each position presenting the desired cross-sectional area for gas flow through the valve most suitable for the particular round tired.

A further feature of the invention is the provision of a relatively small, compact valve device operative to insure that the power supplied to the action is substantially uniform in spite of variations in power of propellant charges.

A further feature of the invention is the provision of a gas control device in a gas operated firearm where the control device is disposed between the firearms barrel and the gas cylinder.

A further feature of the invention is the provision of a gas operated rearm wherein the gas cylinder is so constructed and arranged that it operates both as `an inertia member and a gas cylinder; in functioning as an inertia member the cylinder is operative to control the passage of `gas from the barrel to the working piston.

A further feature of the invention is the provision of la sensing device in a gas operated firearm where the sensing device takes the form of a gas cylinder operative to sense selectively the power differential generated by light and heavy loads red in the lireann.

A further feature of the invention is the provision of an exceedingly simple gas control device in a gas operated firearm where the simplicity stems from the utilization of the gas cylinder as an inertia member.

A control device embracing certain features of the invention may include a firearms barrel, a tubular magazine, a combined gas cylinder and inertia member carried by the barrel, la working pist-on having a power cavity carried by the cylinder and operatively connected to au action slide, conduit means providing a passage for gas characterized by a continuous path leading from the interior of the barrel through said cylinder and through said piston to said power cavity, said combined cylinder and inertia member being movable from a first position wherein there is a maximum opening in said conduit means to a second position wherein there is a minimum opening in said conduit means, said iirst and second positions corresponding to the recoil influence of light and heavy powder loads, respectively, upon said member, said member being thus operative to sense the power characteristics of each powder load tired in the firearm.

Other features and advantages of the present invention will become more apparent from the succeeding speci` ication when read in conjunction with the Iappended drawings, in which:

FIG. l is a vertical section of a portion of a gas operated firearm with which the principles of the present invention may be associated;

FIG. 2 is an enlarged view of Ia portion of the illustration of FIG. l showing the disposition of the combined gas cylinder and inertia member in the first or light load position;

FIG. 3 is a view similar to FIG. 2 showing the control device in the second or heavy load position; and

FIG. 4 is a view of an alternative embodiment of the invention wherein the magazine tube is extended to the right to `form a casing or housing for the combined gas cylinder and inertia member.

Referring now to the drawings, there is shown `a lirearms barrel lil connected to a gas cylinder l1. The gas cylinder 11 is movable relative to the barrel 10 and to this end is slidably supported in the bracket 12. The left end of the cylinder is supported by a magazine tube 13 rigidly xed to the rearm as `at 14.

The forward end of the magazine tube is formed with a lug 16 upon which the cylinder 1l is freely movable through a limited stroke in reciprocatory fashion `and along 1a path which is generally parallel to the longitudinal axis of the firearm.

The forward end of the `gas cylinder is enclosed by means of a cap 17 threadedly engaging the bracket -12 as shown in FIG. 1.

Disposed within the gas cylinder 11, held in the position shown by a coil spring 16, is a working piston 19 having a power ycavity 21. Note that the coil spring 1S encircles the lug 16 and is also operative to retain the movable 'gas cylinder in its extreme left or static position as shown in FIG. 1.

'In conventional fashion the working piston 19 is connected to an action slide 22. The slide is movable to and fro along the longitudinal taxis of the firearm as the working piston is driven by gas pressure impinging upon the internal surface of the power cavity 21. A slot 23 is formed in the cylinder 11 to provide clearance for the reciprocatory motion of the action slide and piston.

As stated previously, the disposition of the cylinder 11 and the piston 19 shown in FIG. l represents the static or normal position of these members prior to firing.

Conduit means, indicated generally by the reference numeral 24, are provided for effecting a continuous path for the passage of gas from the interior of the barrel to the power cavity 21 of the piston. This conduit means is composed of openings 26, 27, 28 `and 29 formed in the barrel 16, the bracket 12, the cylinder 11 and the piston 19, respectively.

The operation of the control device occurs in the following fashion:

With the various elements of the control device disposed in the static position, as shown in FIG. l, the firing of a round will cause the entire weapon to recoil to the rear while the combined gas cylinder and inertia element 11, by virtue of its inertia, will tend to resist motion and remain fixed relative to space; for example, the cylinder 11 will move forward relative to the firearm. This relative motion depends upon the degree of recoil acceleration of the firearm which is, in turn, a function of the type of ammunition being fired.

The disposition and size of the opening Z8 formed in the cylinder -11 is so selected that upon firing light loads, relative motion between the main body of the firearm and the gas cylinder 16 yoperates to uncover a maximum 'aperture for the passage of gas from the barrel 10 to the power cavity 21, as shown in FIG. 2. This maximum opening, sometimes referred to as the first position of the combined gas cylinder and inertia member, results from the fact that upon firing a light load, the main body of the firearm has moved or recoiled to the rear a speciiic increment while the inertia of the gas cylinder is suicient to resist motion yand the relative position of the overall firearm and gas cylinder changes from the static condition shown in FIG. 1 to the light load position shown in FIG. 2.

Oorrespondingly, upon firing a heavy or magnum load, the relative motion between the gas cylinder 11 and the main body of the Weapon 'is of a much higher degree with the result that there is a longer stroke of relative motion wherein the gas cylinder 11 moves to a second position shown in FIG. 3, sometimes referred to as the heavy load position.

Note that in the heavy load position, the gas cylinder 11 operates to restrict or throttle the conduit means 24 effective to reduce the volume of gas impinging upon the interna-l surface of the power cavity 21.

Obviously, the gas cylinder 11 may lassume a variety of positions between those `designated as the first and second positions depending upon the range of power developed in cartridges whose power characteristics fall within light loads and heavy loads.

In effect, then, the control `device is operative to insure the application yof a substantially uniform level of kinetic energy to the working piston 19 in that the gas cylinder 16, by virtue of its movable mounting, is free to sense the severity of recoil, a direct function of the power of the load fired in the weapon, and reacts by automatically positioning the cylinder with respect to the main body of the weapon operative to admit more or less `gas under pressure into the power cavity 21 as the power of the load dictates.

The FIG. 4 embodiment of the invention functions generally in the same fashion as the embodiment of FIGS. l, 2 and 3. The chief dierence is a structural one wherein the power cavity is `enclosed in -a casing or housing 29 to igive added support and rigidity to the movable cylinder 1119. Stops 111 are also provided to retain the cylinder in the static position in opposition to the urging of the coil spring. As desired, the casing 29 may be fabricated as shown in FIG. 4 as an extension of the tubular magazine.

In this arrangement of the invention, it is also necessary to provide an additional slot 31 in the casing 29 to afford clearance for an action slide 220.

While the present disclosure presents two embodiments of the invention, it is yanticipated that a variety `of modiiications and changes may be devised without departing from the spirit and scope of the invention.

What is claimed is:

l. ln a gas operated firearm including a barrel and a tubular magazine, the improvement vcomprising a gas cylinder movably carried by the barrel, said cylinder functioning as an inert-ia member, a power piston having a power cavity carried by the cylinder and operatively connected to an action slide, conduit means providing a passage for gas characterized by a continuous path leading from the `interior of the barrel through said cylinder and through said piston to said power cavity, said cylinder being movable from ya first position wherein there is a maximum opening in said conduit means to a second position wherein there is a minimum opening in said conduit means, said first and second positions corresponding to the recoil influence of light and heavy powder loads, respectively, upon the inertia of said cylinder, said cylinder being thus operative to sense the power characteristics of each powder load fired in the rearm.

2. In a gas operated firearm including a barrel -and a tubular magazine, the improvement comprising a gas lcylinder movably carried by the barrel, said cylinder functioning as an inertia member, a power piston carried by the cylinder and operatively connected to an action slide, conduit means providing a passage for gas characterized by `a continuous path leading from the interior of the barrel to said piston, said cylinder being movable from a first position wherein there is `a maximum opening in said conduit to a second position wherein there is a minimum opening for the passage of gas, said first and second positions corresponding to the recoil inuence of light and heavy loads, respectively, upon the inertia of said cylinder, said cylinder being thus operative to sense the power characteristics of each load iired in the firearm.

3. The rearm of claim 1 wherein the cylinder is housed in xa casing where the casing is contiguous with and forms a part of the magazine.

4. The firearm of claim l wherein one end of the cylinder is slidably supported by the magazine.

Schaich Oct. 15, 1946 Sefried Sept. 27, 1949 

